1. Field of the Invention
The present invention relates in general to digital data processing and in particular to circuits and methods for implementing audio Codecs and systems using the same.
2. Description of the Related Art
The ability to process audio information has become increasingly important in the personal computer (PC) environment. Among other things, audio is important in many multimedia applications, such as gaming and telecommunications. Audio functionality is therefore typically available on most conventional PCs, either in the form of an add-on audio board or as a standard feature provided on the motherboard itself. In fact, PC users increasingly expect not only audio functionality but high quality sound capability.
One of the key components in most digital audio information processing systems is the Codec (coder-decoder) unit. Among other things, the Codec converts input analog audio information into a digital format for processing by a companion digital audio processor. The digital processor for example may support sample rate conversion, SoundBlaster compatibility, wavetable synthesis, or DirectSound acceleration, among other things. The Codec also converts outgoing signals from the audio processor from digital to analog format for eventual audible output to the user. The Codec may also mix analog and/or digital audio streams.
Thus, to meet the demands of increasingly sophisticated computer users, the need has arisen for new circuits and methods for implementing audio Codecs, and systems using the same. Among other things, such circuits and methods should provide for the implementation of Codecs for use with high quality sound systems and should support such features as stereo full-duplex coding/decoding, CD differential input, mono microphone input, and headphone output.